. >> i felt like she was my twin. >> partying with friends. somehow she disappeared. >> they said, are you with kenya? i said, no, i thought she was with you. >> where was she? clues found on a surveillance tape and reports from witnesses. >>> this one left for dead. was evil stalking young women? >> both dark hair, both pretty girls. it was chillingly similar. >> in the history of my department, that's never happened. >> and then finally, far from the city, the truth revealed on a country road. >> he got out of the car and let out this scream. >> and an act of courage from a woman who refused to be a victim. >> and i won. >> she made her voice heard, and tonight we invite you to tell us what you're thinking with the debut of dateline chatline, a new web app that brings together your conversations on facebook and twitter, giving you a chance to chat with correspondent chet morrison live as the clues unfold. now, go inside "a deadly connection." >> welcome to "dateline," everyone. i'm lester holt. it's friday night, and someone love, maybe one